Control device for pneumatic dispatch tube apparatus



s. OLSON 1,846,449

CONTROL DEVICE FOR PNEUMATIC DISPATCH TUBE APPARATUS Feb. 23, 1932.

Filed Jan. 25, 1950 2 Sheets-Sheet 1 In? T? nAAn//// O M a ///-7-7 M 1 2 @deglbr a ffoffle 6.

S. OLSON Feb. 23, 1932.

Filed Jan. 25, 1950 2 Sheets-Sheet 2 Patented Feb. 23, 1932 UNlTED STATES IPATEN OFFIQE QAMUEL OLSON, OF OAK IABK, ILLINOIS, ASSIGNOR "IO SAMUEL OLSON & COMPANY, INC., OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS CONTROL DEVICE FOR PNEUMATIC DIEJPATOI-I TUBE APPARATUS Application filed January 25, 1930. Serial No. 423,329.

This invention relates to controlling devices lor pneumatic dispatch tube apparatus, and more specifically to automatically actuated devices adapted to be used in connection with stems of the minimum flow or partial llow type. By means of these control devices the system is almost instantai'ieously provided With full carrier impelling air flow upon the insertion of a carrier in the tube for transmission, and likewise the flow of air is reduced to a partial flow promptly upon the discharge of the carrier from the tube. lo. prior devices it has usually been necessary to provide some sort of timing mechanism by virtue of which the valve proper was closed a liter a predetermined interval. The disadvanta ol the timing devices resides in the fact that the valve may often be positively held open for a time after discharge of the carrier, pcrn'litting full carrier impelling air How thioi'sgh. the system while the timing device is functioning, which results in a substantial waste of power.

One of the objects of this invention is to provide a dev'ce of the character mentioned in which the valve proper is relatively sensitive so as to be opened and permit full carrierinipelling air flow in the transmission tube almost in;tantancously by the increased vacuum caused by the insertion of a carrier therein, and likewise responding readily for closing and shutting off the full carrier-impelling air tlow the transi'nission tube upon the discharge of the carrier from said tube.

Another object of this invention is to produce an improved controlling device of simplified and relatively compact constructicn which will effect a substantial saving of power.

A further object is to produce an improved control device provided with a battle member positively connected to the valve member, and arranged for receiving the impact of the Final gust of air resulting from the discharge oi? a carrier from the tube so as to utilize this :lorce for moving the valve member to closed position, and thereby restoring partial flow in the system.

it still further object of this invention resides in the provision of an improved control device constructed so as to ensure positive closure of the valve member when suctionproducin means oi the system is shut off. It consists in the elements and features of con- Str'UCtlOll herein shown and described, as indicated by the claims.

In the drawings:

L more 1 is a new illustiating somewhat diagrannnatically a pneumatic dispatch tube item employing a control device embodying the present invention.

Figure 2 is a sectional view taken substantially at a medial plane through my improved control device.

Figure 3 is a transverse view, partly in section, taken substantially as indicated at the line 3-3 on Figure 2.

Figure 4 is a sectional view through a control device of modified construction.

In the pneumatic dispatch tube circuit illustrated in Figure 1 ol the drawings, the numeral 1 indicates a suction or vacuum drum which is connected by a pipe, 2, to the control device embodying the present invention, and indicated generally at 3. It may be understood that the drum may be retained under reduced pressure or partial vacuum by any suitable means, such as a suction pump (not shown). The opposite end of the control device is connected by a pipe, 4:, to the line proper which consists of two transmission tubes, 5 and (3, constituting the outgoing and return tubes respectively, for a pair of stations which they serve. The control device is connected to one of the transmission lines for regulating the flow of air through the complete circuit, and preferably these control. devices wl'1cn there are a plurality of circuits,are arranged at a common or central station. At the station adjacent the control device the transn'iission tube, 5, is provided with a bell-shaped mouth, 7, through which a carrier may be inserted for transmission to the other station at the opposite end of said tube, 5, and discharged through a spring flap door, 8, at said remote end of the tube, This spring flap door is connected to a coupling, 9, which connects the ends of the transmission tubes, 5 and 6, at the station remote from the control device,

and serves to provide a continuous passage from the control device to the remote station and return. This header member is also provided with a spring flap, 10, for closing the transmission tube, 6, through which flap car riers may be inserted for transmission to the station adjacent the control device, and discharged through the spring flap door, 11, at the end of the transmission tube, 6, and mounted on the header member, 12, which serves as a coupling between the transmission tube, 6, and the pipe, 4. These spring-closed flaps provide substantially air-tight closures for the ends of the tubes so as to make a closed continuous circuit from the bell-shaped mouth, 7, to the discharge end or" the tube, 5, and thence to the discharge end of the tube, 6, so that the necessary suction may be produced for impelling carrier through the tubes from either station to the other.

It is to be understood tl any substantial reference in the description or claims to the connection of the transmission tube to the control device, may be taken to include the pipe, 4, together with the line, 6, or both lines 5 and 6.

The control device, 3, which regulates the flow of air through the tubes, includes a hous ing, 14, provided with a valve port, 15, which is controlled by a disk-type valve, 16, mount ed on a reciprocatory valve stem, 17 which is journaled at its upper end in a web portion, 18, of said housing, and at its lower end in the lower wall of the housing. The web portion, 18, is designed to provide a flange for securement of the periphery of a pneumatic diaphragm indicated at 19, which is rigidly secured at its center to the valve stem, 17. The wall of the housing intermediate the web, 18, and the pneumatic is provided with an aperture, preferably having a screen, as indicated at 20, for excluding dust while permitting the chamber, 21, intermediate the pneumatic and the web, 18, to be constantly exposed to atmospheric pressure; the upper side of the pneumatic, as will be seen from the drawings, is also constantly subject to the pressure in the transmission tube. Said valve stem has a portion projecting upwardly be yond the pneumatic, to which projection is rigidly secured a disk-type bafile member, 22, which substantially registers with the port, 4 of the housing connecting to the transmission tube, 4, and the battle is so dimensioned as to substantially occupy the same area as the pneumatic in axial registration therewith.

The cover portion, 14*, of the housing is formed on its under side with a deflector surface, 24, which is formed concentrically of the valve stem and extends over the bathe in an are from one side of the opening, 4 to the opposite side. As may be seen in the drawings this deflector is provided with a curved surface for directing the air current toward the bafiie, 22. It will be apparent that by reason of this deflector, the air current, and more especially the heavy blastof air which results from the discharge of a carrier from the transmission tube, will be directed by the deflector in such a manner as to substantially distribute its impact or force over the entire area of the baffle, by reason of which the pneumatic is forced downwardly, causing the valve member, 16, to close the valve port and restore partial flow to the system. I

The lower end of the valve stem, 17 projects through the bottom of the housing and is provided with a coil spring, 26, which reacts against the housing at one end and against a stop shoulder, 27, at the outer end of the valve stem, and is arranged for normally tending to yieldingly hold the valve member to its seat. To protect the spring and render the control device as a whole more foolproof, I provide a casing, 28, for enclosing the spring member and the lower end of the valve stem, which casing is secured to the valve housing, 14, by screws, 30.

Encompassing an intermediate portion of the stem, 17, in the exhaust tube side of the housing is a second coil spring, 32, abutting at one end against the inside of the wall of said housing opposite the spring, 26, and with its other end engaging a stop shoulder, 33, on said stem below the valve member. As may be seen in the drawings, this spring, 32, exerts a force in the direction in opposition to spring, 26, tending to move the valve member off its seat. This spring member, 32, serves as a buffer for cushioning the impact of the valve member as it engages its seat,"

and also tends to offset the force of the spring, 26, to assist in causing movement of the valve member in opening direction when a carrier is introduced in the transmission tube. It may be understood that the potential energy or force stored in said spring, 32, when fully compressed and when the valve member is in closed position, is less than the counteracting energy stored in the coil spring, 26; the difference in these pressures. or resultant force acting on the valve stem is in the direction for holding the valve member on its seat. It may also be understood that when the valve member is in full open position, as illustrated in Figure 2, the coil spring, 32, has been substantially released so that it practically exerts no force or has no effect in tending to hold the valve member in such open position.

Since in systems of this character it is necessary to have a partial flow or minimum flow of air to initiate opening of the valves, 1 provide a by-pass around the valve member consisting in an aperture, .35, formed in the housing, 14, registering with the chamber, 36, which in turn communicates directly with the main chamber of the housing on the upper side of the valve member which is subjected to the pressure in the trans its force in valve opening direction.

vmissiontube. Forvarying the partialiflow of air through the system, anadjusting screw,

37, is-provided for controlling the effective area of the aperture, 35.

The operation of this control device is substantially as follows lVhen there is no carrier in the transmission tubes, the valve member, 16, is held to its seat by the coil spring, .26,counteracting the force of spring, 32,and the force created by :the slightly reduced pressure on the upper side of the pneumatic, which by reason of the atmospheric pressure in the chamber, 21, on

mission tube, 4, is substantiallyreduced by the partial flow in the system and almost instantly thepressure on the upper side of 3 the pneumatic is so reduced or the vacuum increased to such an extent that the atmosthe spring, 26, for permitting full carrierimpelling air flow through the system.

After the carrler has been discharged from the transmission tube, the heavy blast or follow-up gust of air which results from the discharge of the carrierfrom the tube,

will impinge on thebaiiie member, .22, with such momentum, (whlle simultaneously producing substantially atmospheric pressure at the upper side of the pneumatic) as to compress the spring, 82, and almostinstantaneously force the valve member to its seat, thuspermitting the spring, 26, to come into play for assisting this movement; and when the valve member is once seated, it will be held in such position, substantially without the assistance of the springs, by reason of the suction or reduced pressure acting on the under side of the valve member, which suction is substantially that of the vacuum drum, while the upper side of the valve memher is subject to substantially atmospheric pressure by reason of its being exposed to the pressure in the open transmission tube. And in case the source of suction in the system is shut down, the valve will be positively held to its seat by the spring, 26, which, as above mentioned, is slightly stronger than spring, 32, so as to counteract This arrangement is particularly advantageous in systems employing a large number of control devices because it ensures that all the control devices will be closed at the time the system is agaln put into operatiomand thus avoids over-loading the motor, which would occur in attemptingito build up sufficient suction foroperation of the system, it several of the valves remained open.

In the modified construction illustrated in Figurei, the control device is provided with a housing, 40, having a valve port, 41, controlled by -a disk-type valve member, 42, mounted on .a reciprocatory stem, 4-3, journaled atits upper end in a curved web or deflector portion, 44, and at its lower endin thebearing of the bottom plate, 45, of the housing.

As will be seen in the drawings, this valve member is. arranged for closing toward the direction of flow of air through the system,

which is contrary tothe operation of the device shown in F1gure2. A 0011 spring, 46,

circumscribes the lower portion of the'valve stenrand reacts between the bottom plate, 45, and the housing proper, normally tending to move the valve member to its seat. posed to one side of the path of airflow through the control device, is a pneumatic,

-47, subjected at one side toatmospheric pressure through vent apertures, 48, and at its other side to the pressure in the transmission tube, 4. Rigidly associated with thepneuinatic isra stem, 49, which extends through thepneumatic and is connectedto'an arm, 50, of the bell crank, 51, whose other arm, 52, is connected to the upper end of the valve stem, 40, as may be seen in the drawings. This bell crank member is pivoted at 52, on

.a lug, 58, on the interior ot'the valve casing, and serves to impart movement'to the valve stem under the control of the pneumatic.

Circumscribing the outer end of the stem, 49,

is a spring, 55, reacting between the housing and a stop, 56, on the outer end ofsaid stem, and normally tending tobuckle the pneumatic in an outward direction for rocking the bell crank lever to move the valve member to its seat,this being in addition tothe force of the spring member, 46. Mounted on the inner side of the pneumatic on the stem, 49, is a disk-type battle, 57, of about the same effective area as the pneumatic, and the deflector, 44, opening oii" the transmission tube, 4, is so curved as to directthe flow of air substantially perpendicularly to the baffle member.

Toensure initiating the opening of the valve member, systems of this character must have partial or minimum flow of air, and for this purpose thelower part 01" the housing YVhen there isno carrier in the transmis- Dis- ' sion tube, the valve member is normally on its seat, and a partial or minimum flow of air is permitted through the system; as soon as a carrier is inserted in the transmission tube the pressure in the tube and in the upper part of the controlling device is gradually diminished by reason of the partial flow, and after a very short interval of time the atmospheric pressure on the outer side of the pneumatic will be sufficient to buckle the pneumatic inwardly and overcome the reaction of the springs, 46' and 55. This movement of the pneumatic is imparted through the bell crank lever to the valve member for forcing it downwardly away from its seat to permit full carrier impelling air flow through the system. As soon as the carrier is discharged from the transmission tube, the heavy blast or follow-up gust of air flowing through the tube will be directed by the deflector, 44, so as to impinge directly against the baffle, 57, with a force, which, together with the venting or partial venting of the vinner side of the pneumatic to approximately atmospheric pressure, will tend to buckle the pneumatic outwardly with the assistance of the springs, a6 and 55, and almost instantaneously move the valve to its seat for shutting off full suction from the transmission tube, and restoring the system so as to be ready to repeat the cycle.

It will be apparent from inspection of Figure 4 that this construction is also arranged so that in the event the main source of suction in the system is shut down, the valve member will be positively maintained on its seat by the springs, 46 and 55.

By dispensing with the timing mechanism usually employed in devices of this character, I have produced a relatively compact device of simplified construction, which is capable of conserving a substantial amount of power by causing the valve member to close almost instantly upon discharge of the carrier from the tube.

I claim:

1. In a pneumatic dispatch tube system of the minimum-flow type, including a transmission tube and an exhaust tube connected to a source of suction; a normally closed control device interposed between said tubes and adapted for regulating the flow of air therethrough, a restricted flow of air being permitted when said device is closed, said control device including a casing formed with a valve port, a valve member therefor, means initiating opening of the valve'member in response to the reduced pressure in the transmission tube resulting from the introduction of a carrier therein, and a battle positively connected to the valve member and disposed in the path of air flow and adapted to be actuated by the impingement thereon of the sudden rush of air through the transmission tube. incident to the discharge of a carrier therefrom, for moving the valve member to closed position.

2; In a pneumatic dispatch tube system of the minimum-flow type, including a transmission tube and an exhaust tube connected to asource of suction; a normally closed control device interposed between said tubes and adapted for regulating the flow of air therethrough, a restricted flow of air being permitted when said deviceis closed, said control device including a casing provided with a valve port, a valve member therefor, a pneumatic connected to the valve member and constantly subjected on one side to atmospheric pressure, and at the other side to the pressure in the transmission tube, said pneumatic being directly responsive to the reduced pressure in the transmission tube resulting from the introduction of a carrier therein for initiating opening of said valve member to permit full carrier-impelling air flow through the transmission tube, and a battle positively connected to the valve member and disposed in the path of air flow for receiving-the impact of the sudden rush of air resulting upon the discharge of a carrier from the tube, for having said valve member to closed position.

3. In a pneumatic dispatch tube system of the minimum-flow type, including a transmission tube and an exhaust tube connected to a source of suction; a normally closed control device interposed between said tubes and adapted for regulating the flow of air therethrough, a restricted flow of air being permitted when said device is closed, said control device including a casing provided with a valve port, a valve member for closing said port, a pneumatic connected to the valve member and constantly subjected on one side 'to atmospheric pressure and at the other side to the pressure in the transmission tube, said pneumatic being directly responsive to pressure variations in the transmission tube resulting upon the introduction or discharge of a carrier, for causing said valve member to open or close, respectively, and a bafile positively connected to and movable with the pneumatic and disposed in the path of air flow for receiving the impact of air following the discharge of a carrier, and thus assisting the pneumatic in promptly closing the valve member.

4. In a pneumatic dispatch tube system of the minimum-flow type, including a transmission tube and an exhaust tube connected to a source of suction; a normally closed control device interposed between said tubes and adapted for regulating the flow of air therethrough, a restricted flow of air being permitted when said device is closed, said control device including a casing provided with a valve port, a valve member for closing said port, a spring arranged for yieldingly holding the valve member in closed'position. a

pneumatic connected to the valve member and constantly subjected on one side to atmospheric pressure and at the other side to the pressure in the transmission tube, said pneumatic being directly responsive to pres sure variations in the transmission tube resulting upon the introduction or discharge of a carrier, for causing said valve member to open or close, respectively, and a battle positively connected to and movable with the pneumatic and disposed in the path of air flow for receiving the impact of air following the discharge of a carrier, and thus assisting the pneumatic in promptly closing the valve member.

5. In a pneumatic dispatch tube system of the minimum-flow type, including a transmission tube and an exhaust tube connected to a source of suction; a normally closed control device interposed between said tubes and adapted for regulating the flow of air there through, a restricted flow of air being permitted when said device is closed, said control device including a casing provided with a valve port, a valve member for closing said port, a pneumatic connected to the valve member for moving the same to open or closed position in response to pressure variations in the transmission tube resulting from the introduction or discharge of a carrier there froi'n, said pneumatic including a flexible member constantly exposed on one side to atmospheric pressure and at the other side to the pressure in the transmission tube, and a 7' baiile disposed in the path of air flow tor receivin g the impact of the sudden rush of air in the transmission tube incident to the discharge of a carrier, said baffle being arranged and associated with the flexible member of the pneumatic for directly transmitting the ei'l'ective ifOICG exerted thereon to a relatively small central area of said flexible member tor actuating the same and thereby causing substantially instantaneous closing of said valve member.

6. In a pneumatic dispatch tube system of the minimum-flow type, including a transmission tube and an exhaust tube connected to a source of suction; a normally closed con trol device interposed between said tubes and adapted for regulating the flow of air therethrough, a restricted flow of air being permitted when said device is closed, said control device including a casing provided with a valve port, a valve member for clos ing said port, a pneumatic connected to the valve member for moving the same to open or closed position in response to pressure variations in the transmission tube resulting from the introduction or discharge of a carrier, said pneumatic being constantly ex posed on one side to atmospheric pressure and at the other side to the pressure in the transmission tube, and a battle associated with the pneumatic and arranged for receiving the impact caused by the sudden rush of air in the transmission tube incident to the discharge of a carrier, for assisting the pneumatic in effecting substantially instantaneous closure of the valve member, said casing being provided with a deflector for directing the air against said baffle and insuring a maximum effect from said rush of air.

7. In a pneumatic dispatch system of the minimum-flow type, including a transmission tube and an exhaust tube connected to a source of suction, a normally closed control device interposed between said tubes, and adapted for regulating the flow of air therethrough, a restricted flow of air being permitted through the tubes When said control device is closed, said control device including a casing having a valve port, a reciprocating valve member for closing the port, and adapted for opening against the iiow of air through the tube, a stem connected to the valve member, and a pneumatic positively connected to the stem, and direct- 1y responsive to pressure variations in the transmission tube caused by the introduction or discharge oiv a carrier, for opening or closing the valve, said pneumatic being disposed adjacent the path of flow of air, but arranged for responsive movement perpendicularly thereto.

8. In a pneumatic dispatch system of the minimum-flow type, including a transmission tube and an exhaust tube connected to a source of suction; a normally closed control device interposed between said tubes, and adapted for regulating the flow of air therethrough, a restricted flow of air being permitted through the tubes when said control device is closed, said control device including a casing having a valve port, a reciprocatory valve member for closing the port, and adapted for opening against the flow of air through the tube, a stem connected to the valve member, means for opening the valve in response to a reduction of pressure in the transmission tube caused by insertion of a carrier therein, and a baliiepositively connected to said stem and disposed directly in and perpendicular to the path of flow of air from the transmission tube, for receiving the impact of the sudden rush of air therein incident to the discharge of the carrier from said tube, for moving said valve member to closed position.

9. In the construction defined in claim 8, said baffle having an area considerably greater than the cross-sectional area of the opening from the transmission tube, and said casing being formed with a deflector tor effectively directing the air flow against said baffle.

10. In a pneumatic dispatch system of the minimum-flow type, including a transmission tube and an exhaust tube connected to a source of suction; a normally closed control iii) device interposed between said tubes, and

adapted for regulating the flow of air therethrough, a restricted flow of air being permitted through the tubes when said control device is closed, said control device including a casing having a valve port, a re cipr-ocatory valve member for closing the port, and adapted for openingagainst the flow or" air through the tube, a stem connected to the valve member, a spring yieldingly holding the valve member seated, a pneumatic mounted in said casing and connected to the stem and responsive to pressure variationsin the transmission tube resulting from the insertion or discharge of a carrier therefrom, for causing movement of the valve memberto open or closed position respectively, a baiile rigidly connected to the stem and disposed directly in and perpendicular to the path of air flow from the transmission tube, for receiving the impact of the sudden rush of air therein incident to the discharge of a carrier from the tube, for causing the valve member to move to closed position promptly upon discharge of the last carrier from the transmission tube.

11. In a pneumatic dispatch system of the minimum-flow type, including a transmission tube and an exhaust tube connected to a source of suction; a normally closed control device interposed between said tubes and adapted forregulating the flow of air therethrough, a restricted flow of air being permitted through the tubes when said control device is closed, said control device including a casing having a valve port, a reciprocatory valve member for closing the port, and opening against the flow of air through the tube, a stem connected to the valve member, a spring yieldingly holding the valve member seated, a pneumatic mounted in said casing and connected to the stem and responsive to pressure variations in the transmission tube resulting from the insertion or dis charge of a carrier therefrom, for causing movement of the valve member to open or closed position respectively, a baffle connected to the stem and disposed dir ctly in and perpendicular to the path of air flow from the transmission tube, for receiving the impact of the sudden rush of air therein incident to the discharge of a carrier from the tube, for causing the valve member to move to closed position promptly upon discharge of the last carrier from the transmission tube, said batlie having an area considerably larger than the cross-sectional area of the opening connecting the transmission tube, a substantial portion of the baffle extending later ally beyond said opening, said casing having formed therein a deflector surface opposite and adjacent the outer periphery of the portion of the baiile extending beyond the open- 65 ing for insuring action of the air pressure over substantially the entire area of said baffle. I

12. In a pneumatic dispatch system of the minimum-flow type, including a transmis sion tube and an exhaust tube connected to a source of suction; a normally closed con= trol device interposed between said tubes and adapted for regulating the flow of air therethrough, a restricted flow of air being permitted through the tubes when the control device is closed, said control device including a casing formed with a valve port whose axis is disposed substantially parallel to and in registration with the transmission tube opening, a reciprocatory valve member for closing the port, a stem connected to said valve member, a pneumatic diaphragmdisposed at one side of and parallel to the path of air flow from the transmission tube, and means connecting the pneumatic to the valve stem, saidpneumatic being constantly exposed at one side to atmospheric pressure and at the other side to the pressure in the transmission tube, and being responsive to pressure variations caused by the introduction or discharge of a carrier from the transmission tube, for causing opening or closing of said valve member. I

13. In the construction definedin claim 12, said casing being formed with an arouate deflector for directing the sudden rush of air, incident to the discharge of a carrier, perpendicularly against the pneumatic.

14. In the construction defined in claim 12, said valve member being arranged for opening in the direction of air flow, and a spring acting to yieldingly urge said valve member to closed position.

- 15. In a pneumatic dispatch system of the minimum-flow type, including a transmission tube and an exhaust tube connected to a source of suction; a normally closed control device interposed between said-tubes and adapted for regulating the flow of air therethrough, a restricted flow of air being per-' mitted through the tubes when the control device is closed, said control device including a casing formed with a valve port disposed substantially parallel to and in registration with the transmission tube opening, a reciprocatory valve member for closing the port, a stem connected to said valve member, a pneumatic diaphragm disposed at one side of and parallel to the path of air flow from the transmission tube, means connecting the pneumatic to the valve stem, said pneumatic being constantly exposed at one side to atmospheric pressure and at the other side to the pressure in the transmission tube, and being responsive to pressure variations caused by the introduction or discharge of a carrier from the transmission tube, for causing opening or closing of said valve member, and a baflle rigidly connected to the pneumatic and disposed in the path of air flow for receiving the impact of the sudden rush of air incident to the disclurrge of a carrier, for assisting the pneumatic to cause prompt closure of the valve member.

1&5. in a pneumatic dispatch system of the minimunrflow type, including a transmission tube and an exhaust tube connected to a source of suction; a normally closed control device interposed between said tubes and adapted for regulating the flow of air therethrough, a restricted How of air being permitted through the tubes When the control device is closed, said control. device including a casing formed with a valve port disposed substantially parallel to and in registration with the transmission tube opening, a reciprocatory valve member for closing the port, a stem connected to said valve member, a pneumatic diaphragm disposed at one side of and parallel to the path of air flow from the transmission tube, means connecting the pneumatic. to the valve stem, said pneumatic being coi'lstantly exposed at one side to atmospheric pressure and at the other side to the pressure in the transmission tube, and being responsive to pressure variations caused by the introduction or discharge of a carrier from the transmission tube, for causing opening or closing of said valve member, a battle disposed adjacent the pneumatic, parallel to the direction of air flow through the tubes, and a deflector arranged for directing perpendicularly against said battle the sudden rush of air resulting from the discharge of a carrier from the transmission tube, for assisting the pneumatic to cause said valve memher to be instantaneously moved to closed position.

11?. In the construction defined in claim 16, said deflector including an arcuate member of approximately 90 angular extent, and a shirt portion depending therefrom and disposed adjacent and substantially parallel to said battle,

.' 8. In a pneumatic dispatch system of the i'nininunn flow type, including a transmission tube and an exhaust tube con nected to a source of suction; a normally closed control device interposed between said tubes and adapted for regulating the flow of air therethrough, a restricted flow of air being permitted through the tubes when the control device is closed, said control device including a casing having a valve port disosed substantially parallel to and in registration with the transmission tube opening; a rcciprocatory valve member for controlling said port, a stem connected to said valve member, a pneumatic disposed at one side of the path of air flow from the transmission tube and movable in a direction substantially perpendicular thereto; and a bell crank connecting said pneumatic to the valve stem, said pneumatic being constantly exposed at one side to atmospheric pressure and on the other I" mg opening or closing or said valve member.

In testimony whereof, I have hereunto set my hand at Chicago, Illinois, this 15th day of January, 1930.

SAMUEL OLSON. 

